Q: How do I get my devices to constantly stream to iCloud?

I have an iPad, iPad Mini, and an iPhone 5. I can't seem to be able to get them to all upload photos and videos to my iCloud. And, yes, I am connected to iCloud. Today I was taking videos (only five, 3-minute videos) when I ran out of storage. I tried to take pictures on all three devices; all of them claimed they were out of storage.

iPad:

Storage: Used - 11.9 GB, Available 398 MB

iCloud: Available - 1.0 TB

iPad Mini:

Storage: Used - 12.3 GB, Available 0 bytes

iCloud: Available - 1.0 TB

iPhone 5:

Storage: Used - 11.6 GB, Available 0 bytes

iCloud: Available - 1.0 TB

I'm connected to my iCloud on three devices. However, I always seem to be out of storage at the worst possible times. I have 1.0 TB available, but according to the cameras, "There is not enough available storage to take a photo." How do get my pictures and videos to constantly upload/stream to my iCloud so that I have enough storage to take pictures and videos?

On all three devices, these are on/selected:

iCloud Photo Library

Upload to My Photo Stream

Upload Burst Photos

iCloud Photo Sharing

Optimize iPhone Storage

This has been going on for months! I would appreciate it more than you'd know if there was an answer to my dilemma.